PROJECT SUMMARY Cancer-related cognitive dysfunction (CRCD) is a significant problem, affecting up to 75% of patients receiving chemotherapy. Older adults are at greater risk of developing CRCD which can negatively affect their functional independence and quality of life. Memory and Attention Adaptation Training (MAAT) is a promising tool that improves perceived cognition in younger cancer survivors with CRCD. For older adults with cancer, MAAT could be delivered alongside chemotherapy to mitigate the development of CRCD (when risk is highest) and CRCD-related effects on functional independence for older adults. However, MAAT will require adaptation to meet the unique needs of older adults to optimize usability and efficacy for this population. I have worked with my mentors to develop preliminary data for this proposal, demonstrating: 1) older patients and caregivers are concerned about the cognitive effects of chemotherapy; 2) nearly half of patients with breast cancer receiving adjuvant chemotherapy report a clinically significant decline in self-reported cognition; 3) it is feasible to study behavioral interventions in clinical trials for older adults with cancer receiving chemotherapy; and 4) older adults receiving chemotherapy are interested in participating in a clinical trial evaluating a cognitive intervention. The overarching goal of this proposal is to adapt MAAT for older adults using input from patient and caregiver stakeholders, and subsequently gather data on the preliminary effects of the adapted MAAT (MAAT-Geriatrics [G]) on perceived cognition, objective cognitive measures and functional independence in 85 older adults with breast cancer receiving adjuvant chemotherapy compared to active control condition in a 2- arm pilot randomized controlled trial (RCT). The research plan combines the use of standardized quantitative measures of cognition and functional independence with semi-structured interviews (mixed methods), so that data from both can be integrated to gain a better understanding of MAAT-G's effects that are not fully captured by traditional quantitative measures alone. Dr. Magnuson is an emerging leader in the field of geriatric oncology with a focus on cognition. However, in order to become an independent researcher who designs and implements behavioral interventions to prevent cognitive decline and improve outcomes for older adults with cancer, she requires additional training and experience in: 1) CRCD measurement and assessment of biologic mechanisms of CRCD; 2) the design, execution and analysis of RCTs involving cognitive interventions; 3) the design and analysis of mixed methods trials; and 4) development and refinement of her leadership skills. An outstanding mentor team supports this proposal (Mohile/Hurria?geriatric oncology/leadership, Janelsins/Ferguson?CRCD/cognitive interventions, Lin?cognitive aging, Morrow?behavioral interventions, Wittink?mixed methods, Culakova-biostatistics). The training and research plan will position Dr. Magnuson to become one of the few geriatric oncologists studying cognition and cognitive interventions, and develop a much-needed cognitive intervention for older adults at risk for developing CRCD.